This is a season in which nothing should surprise us, but just as it looked as though Everton had stood firm where Liverpool had fallen in the previous round, Oldham Athletic sent another shock wave through this famous old competition.

The game had moved into the final minute of injury time and Everton appeared to have everything under control when Matt Smith headed in a corner and sparked bedlam at Boundary Park. Magnificent, incredible, but such has been the regularity with which top-flight clubs have been humbled in knockout competitions, we might be in danger of becoming blasé.

Oldham were superb. Times are so hard for the club that their players were asked not to swap shirts with Everton’s stars after the game because of the cost of replacing them, but even when they lost control of the midfield battle, even after they had lost the lead Jordan Obita had given them, they refused to yield.

Everton will remain favourites to progress, but you cannot take anything for granted. Oldham, their coffers swelled by the gate receipts this historic cup run has brought them, will go to Goodison Park believing they can win the replay. Bradford City’s incredible feats in the Capital One Cup have reminded every lower league club that anything is possible.

“The draw is the dream result,” said Tony Philliskirk, who as caretaker manager also took charge of Oldham’s youth team against Rochdale that morning.

“It has been hard financially this season for the chairman to keep things ticking over and hopefully the extra money the replay generates helps.

“When the goal went in I was just smiling to myself because I know what it means financially. I looked up at the directors box and they were jumping around more than anyone else.”

Not that Everton were caught unaware. There have been too many shocks this season for complacency and David Moyes sent out the strongest side he could. “Oldham more than deserve the replay,” said Moyes, full of admiration for the way they had come back at his side. “We didn’t get the third goal to kill the game off and there was always a chance this would happen.”

The visitors should still have been far too good for their League One hosts. Relegation is a distinct possibility. The manager who led them to that glorious win over Liverpool, Paul Dickov, has since been relieved of his duties. They have not appointed a successor, Philliskirk taking on the caretaker role while potential candidates are assessed by chairman Simon Corney.

A lack of match fitness had also deprived Oldham of Smith from the start, the tank of a frontman who had bullied Liverpool’s centre-backs and scored twice to take that famous scalp having to bide his time on the bench.

Everton’s coolness disappeared inside the first 15 minutes. Oldham turned defence into attack, clearing a corner as Leon Osman tried to intercept on the halfway line and was rolled by Lee Croft. He darted down the right and managed to thread a low cross through the tiniest of gaps to find Obita. The England Under-19 player, on loan from Reading, side-footed home from six yards.

The lead did not last long, Nikica Jelavic nodding the ball down for Victor Anichebe to turn sharply and smash home an equaliser.

Oldham almost took the lead again, Obita’s shot taking a deflection before spinning against the inside of the post.

Everton began to see more of the ball as Oldham’s players worked tirelessly to close them down. The fear was they would tire and Everton knew the more they made them chase, the heavier their legs would become. Patience would have been a prominent part of Moyes’s half-time team talk, but Oldham also knew they could hurt Everton in the final third.

It set up an intriguing second half. Everton started it brightly and substitute Kevin Mirallas delivered a corner for Phil Jagielka to nod firmly past Dean Bouzanis.

The defending was poor and for the first time Oldham were in trouble, Steven Pienaar creating room for a shot with his quick feet which almost put the tie to bed.

Oldham began to rely on set pieces to threaten Tim Howard’s goal, while Osman almost got on the end of another Mirallas corner.

The home side, though, would not give up and Howard made two excellent saves to keep out Smith before his sensational header.